Low-Level Waste Disposal Facility Confinement

DOE-HDBK-1132-99

The facility should allow retrieval of wastes during the 50-year period following

emplacement and before permanent closure of the facility.

Low-Level Waste Disposal Facility Confinement . Low-level solid waste that

is disposed to the ground should be confined by a site-specific system of

barriers that may include-- but not necessarily be limited to-- waste form, waste

packaging, and the geologic setting.

When site permeability characteristics do not provide the required confinement

capabilities, the confinement system should be augmented by the following:

constructing low permeability walls around the low-level waste,

lining the walls and bottom of the excavated area with low permeability

material, and

other suitable methods for reducing permeability.

Means should be provided to minimize contact of emplaced low-level waste

with water. Active water-control measures should not be required following

permanent closure. Typical requirements for water control are as follows:

Placing a layer of highly permeable material (e.g., sand, gravel) beneath

the low-level waste to channel any percolating water to a sump.

Mounding the soil surface to facilitate surface water runoff.

Use of a suitable low-permeability cover material (e.g., clay) over the

disposal area to prevent contact of the waste by infiltrating rainwater.

This cover material should be protected by a layer of overburden

(e.g., sand, gravel, top soil).

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